


emotions and math

by jennyquill



Series: (trio) they're in love and this is their soundtrack [1]
Category: Supergirl (TV 2015)
Genre: F/F, l-o-v-e is very hard to say
Language: English
Status: Completed
Published: 2017-01-06
Updated: 2017-01-06
Packaged: 2018-09-15 06:18:50
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,938
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/9222950
Author URL: https://archiveofourown.org/users/jennyquill/pseuds/jennyquill
Summary: Love is a chemical, and chemicals usually have equations attached to them. Unfortunately, there’s no equation on how to tell someone that you love them. Lena’s checked.





	

**Author's Note:**

> inspired by margaret glaspy’s really hip song with the same name

.

  


The probability of Lena having Kara all to herself for one night is highly unlikely. She crosses her fingers and takes the bet anyways.

 

Probability is stupid. Probability is especially stupid when it’s after midnight and Lena just wants the odds to bend in her favor for once.

 

“Your phone is ringing again,” she complains.

 

“Tell them to go away.” Kara presses lazy kisses between Lena’s shoulder blades and Lena melts.

 

“It’s probably your sister.” She feels Kara make a face.

 

“I don’t want to think of Alex right now.” The buzzing pauses for a hot second before revving back up again in full, insistent blare. Kara groans, peels herself away from Lena and grumpily strides over to answer her late-night caller.

 

This happens. Kara’s here for fleeting moments before Kara is inevitably gone. Lena’s grown accustomed to her long absences, the silences, the phone calls and the disappearing during the ungodly hours of the night, but still. It’s just a little frustrating. She would never choose this life for herself, but she does choose Kara, so in a way then Lena knows she’s in this for the long ride.

 

Kara speaks into her phone with more bite than usual. Lena shifts where she lays, pulls the covers over herself. The conversation is short and direct, and when Kara hangs up, Lena can practically see the outline of Supergirl taking shape.

 

“I have to go,” Kara says, although it’s kind of pointless. Still, Lena nods.

 

In the weak light from the window, Kara glows. Her camisole strap is falling off one shoulder and hair swept over the other. She stands, not entirely Kara Danvers but not fully Supergirl either.  Lena wants to pull her back underneath the covers, to ask her to be selfish for once, except she knows better.

 

Kara walks over to Lena’s side and kisses her softly. “I’ll be back.”

 

“I know.” Lena sneaks another kiss in. “Go save the world.”

 

When Kara smiles Lena feels it all the way down to her toes.

 

“I’ll see you soon.”

 

Kara leaves in a flurry of movement and shapes and wind which all leaves Lena slightly breathless. Her exit is always a clean one, and Lena’s reaction is always one part in yearning, and one part in awe.

 

She sits up and wraps the sheets over herself. The bed is getting colder by the minute and her head is still fuzzy with pictures of blonde curls and red lips, the smell of lemon and honey lingering on her pillow. Lena groans.

 

The probability of Lena Luthor being highkey whipped by Supergirl is a hundred percent likely.

  


.

  


On the flipside, there’s the situation of when Kara comes back after a fight, adrenaline high and hands fussy. Lena likes this kind of probability a lot better.

 

There’s science involved with why Kara is this way, something about exercising reducing stress and releasing endorphins -

 

Kara’s teeth seek out her pulse point and then she bites  _hard_.

 

Lena forgets.

 

A thigh is shoved between Lena’s legs and she hits the kitchen counter, keening. Kara wedges her way closer, body thrumming and hot under the tightness of her suit. Lena runs her hands over muscle, licks sweat off the regal column of her throat and Kara hisses. Lena’s lifted off the ground and roughly placed on the counter, giggling like a schoolgirl the entire time.

 

Kara nips at her lip, “What?”

 

Lena grips her bicep, smile mischievous. “You’re hot after a rumble.” Kara’s jaw drops.

 

“Since when have you seen West Side Story?” She gives her an incredulous look and Lena tugs on her cape to pull her back to business, already knowing that she’s going to be hounded about this later on but now all she wants to do is kiss her girlfriend senseless.

 

Kara responds almost immediately (“we are _definitely_ watching the movie afterwards”) and refocuses, sliding her hands under Lena’s sweatshirt and grinning into her mouth when her hands meet bare skin.

 

Lena ducks her head and goes to work at Kara’s earlobe. She passes her pulse point and she can feel the fluttering of Kara’s heart, the stream of energy that hasn’t stopped humming since she flew through the open window. She smiles for a different reason.

 

Kara leaves and Kara always comes back, and she comes back to Lena. Sometimes the fighting drains her and she clocks out. Lena will bring whatever she’s working on to wherever Kara’s crashed, run her fingers through blonde locks and whisper soothing things in her ear until her breathing calms. And then there are times like this, times where boots hit the hardwood and stomp around the apartment until they find Lena.

 

Lena welcomes both possibilities, but sometimes she really needs the second one.

 

Her hands travel lower across Kara’s back and lower still until she flips her little skirt, feels Kara shiver when Lena squeezes her ass. Kara, head fully back in the game, wastes no time in shucking off Lena’s pants, mouth back on hers and fingers teasing along her underwear.

 

Lena breathes in Kara’s sighs, her groans, lets her legs spread and her hips lift off of the counter, searching for the bit of friction that Kara’s fingers aren’t allowing her.

 

Lena breaks away to look at her. The most powerful being in the world is wrapped around her, hair a frizzled mess, lips red, chest heaving, eyes dark. Lena drips.

 

Kara’s hand slips past her underwear and slides along the wetness there. Lena lets out a whine, wraps her arms around Kara’s shoulders and buries her head in the crook of her neck.

 

There’s reason to the majority of the decisions that Lena Luthor makes day to day and she lets all of that good logic disappear when Kara finally enters her.

 

She feels Kara’s eyes on her, watching her mouth quiver and eyes roll to the back of her head as she rides her fingers. Kara kisses her sloppily, hungrily, and swallows her moan when she comes, a cocky grin on her face.

 

They stay like that while Lena catches her breath, Kara’s fingers still curled inside her moving slowly, languidly.

 

Lena kisses her soundly. She takes Kara’s face in both hands and brushes her thumbs across the red that dots her face, adorable and sexy all at once and Lena doesn’t know how she does it.

 

“Hi,” she says and laughs a little.

 

“Hi.” Kara Danvers peaks out from under Supergirl’s luster. Lena kisses her again, softer this time.

 

“I missed you.”

 

“I wasn’t gone for long.” Kara wraps her arm tight around Lena’s middle.

 

Lena’s hands move down to Kara’s neck. “I know. I just miss you when you’re not here.” There are more words that get caught in her throat, words she can’t really say right now. She’d rather say them when she had pants on and wasn’t just coming off of an orgasm. Kara looks impossibly soft, such a different color than moments before.

 

Lena wants to bring back the blush that crept up her chest and stained her neck.

 

“But now that you are here…” Lena raises her eyebrow suggestively, pulls Kara forward.

 

Kara grins, wicked, and the probability shifts.

  


.

  


The outliers always mess her up.

 

As much as she wishes, Lena isn’t naive enough to think she could ever have Kara selfishly, knows that Kara would never choose her over her city. Still, she’s always a little heartbroken when Kara rushes away to fly off into the sky, chair wobbling and food still warm on the table.

 

This happens a lot, so then it isn’t really an outlier. Lena grumbles and finishes the rest of her wine in one gulp. She pays the bill and then leaves, seeing no point in waiting for anything else. 

 

Lena stands on the sidewalk outside of the restaurant just as the sun starts to set. She wonders what the sunset looks like from where Kara is, makes a mental reminder to ask her about it later.

 

Later finds her in the office, sheets spread across the white desk, laptop running and pen tapping mindlessly against her chin. A habit she picked up from Lex, probably. Later means that her night has become (expectedly) unexpectedly free and because she was raised in a den of Luthors, she throws her frustrations into her work.

 

She’s in the middle of reading an email from Intel Core, something about thanking her for L-Corp’s generous support and would she please consider buying into their new line of processors and maybe revisit -

 

Her eyes slide to the vase of orchids that stand thoughtfully on the far corner of her desk. It’s a stark splash of color in a monochrome room, gentle hues of purple and pink that seem almost loud against the grey of the walls. Lena smiles. She had found them at her desk one morning along with a handwritten note from Kara which simply said, ‘thinking about you.’

 

Lena wonders what she’s doing at that moment, if she’s struggling or winning, in pain or going through the motions of a day’s work.

 

She thinks about Kara, too.

 

Lena needs to remind herself that she’s technically dating two people at once. While Kara Danvers can spend an evening over drinks and a movie, Supergirl cannot. Two different people equals two different lives and Lena doesn’t know where to insert herself into the equation. She hears that horrible thought again, the one that tells her to leave, to let someone else fill Kara’s time with a less sorry-feeling, self-serving mindset than herself. It wouldn’t be hard, she muses. Kara could give anyone orchids. Three million people in the city, limitless options.

 

But Kara always comes back, and she comes back to Lena, and Lena chooses all of Kara - she chose all of Kara a long time ago.

 

Lena breathes in, breathes out. She needs a break. She drops her pen on the desk and pushes her chair out, walks over to her glass balcony doors and steps out into the night air.

 

Out of habit her eyes scan the skies, searching between stars and supernovas for a familiar figure in tights. She finds nothing. Below her feet, the city is humming with life. She has half a mind to join, maybe stretch her feet and wander the streets like she did when she first came to the city.

 

Kara was her first friend. Supergirl was her second. She took walks with Kara, who showed her the museums and coffee shops, the parks and the bars. They got ice cream at this cute kiosk on 3rd and Bradley...

 

Lena decides against the walk and paces the length of her balcony instead.

 

Sirens wail in the distance. Lena turns her head, looks for flashes of red and blue and -

 

She needs a drink.

 

Lex’s first girlfriend drove him crazy. Lena remembers her, all shy smiles at sixteen, a jean jacket and high ponytail looking out of place in the family’s posh foyer. Lena had asked Lex then, after the awkward dinner, why she drove him crazy.

 

“She was so sweet,” she had said, confused.

 

Lex had gotten this dreamy look in his eyes. He said, voice far off and distant, “it’s the good kind of crazy.”

 

Lena didn’t understand but she nodded anyways because Lex was older and at the age where a lot of stuff he said about girls didn’t make sense.

 

Now, knocking back a shot of whiskey, Lena understands him with horrifying clarity.

 

Probability stated it was only a matter of time, anyways.

  


.

  


It’s not always about the sex. The sex is great, nothing wrong with it, and Lena feels herself blushing just thinking about the word.

 

It’s that it’s sex with Kara.

 

There isn’t anything wrong with that statement either. Lena mentally kicks herself and focuses on Kara’s short breaths, her long neck, her back arching off of the couch, her hands tugging in Lena’s hair.

 

It takes one last swipe of her tongue and Kara’s falling apart.

 

She crawls up Kara’s body, kisses shiny skin lazily, dragging her mouth up over Kara’s chest to her jawline until their eyes meet.

 

Lena feels electric.

 

Kara smiles up at her with the brightest eyes. Lena feels her throat constrict again, emotions tangling up in the stupidest way. She leans down and kisses her instead. Kara giggles, the sound musical and representative of all things good in the world and Lena feels so, so -

 

Kara flips their positions and Lena briefly wonders if logic would be able to tell her how to tell Kara all that she can’t say.

 

Probably not, but Lena wonders anyways.

  


.

  


Kara trudges through the doorway and everything from her posture to her missing shoe tells Lena that the world was not in Kara Danvers' favor that day.

 

“I don’t want to talk about the shoe,” she grumbles when she passes Lena at the kitchen table. Lena suppresses a laugh, raises an eyebrow instead.

 

“Alright.”

 

“It was this blockhead alien that broke into the DEO,” Kara complains from her room. “Tentacles _and_ feet. How extra is that?” There’s some more angry shuffling and a slamming of closet doors. “I mean, if I had twelve extra arms I wouldn’t bother with legs, I’d just adapt like any normal alien and not go on a shoe-hunting spree, wouldn’t you?” She huffs out of her room in cotton pants and worn tank top, hands adorably fisted at her sides, a picture of the most placid superhero in National City, save for the grouchy pout. Lena finds it all really endearing, although she’s sure Kara doesn’t want to hear that.

 

“I’m sorry he did that to you,” Lena closes her laptop, tries very hard not to laugh. All this casual alien talk is still taking her some getting used to, but it’s harmless stories like these that put Lex and her mother’s work into a different light.

 

“She, actually,” Kara mumbles and heads straight to the fridge.

 

“Oh.” Lena makes a face. “Respect.”

 

Kara joins Lena with a pint of chocolate-chip cookie ice cream and a single spoon, her furrowed brow indication enough that she’s in no mood for sharing. It hits her then, that they’ve already spent enough time around each other that she’s able to read her so easily. It should startle her, just like it startled her in her previous relationships, but Lena only feels whole.

 

“How else was your day?” she asks Kara. It comes out of her so fluidly it’s like they’ve been doing this for years.

 

Kara doesn’t miss a beat and jumps into a rant about Snapper’s editing policies and other CatCo code that apparently Snapper doesn’t want to follow but has to. Lena listens with her head leaning against her hand, her work forgotten. They talk easily, naturally, the conversation weaving so soothingly that even the quiet between them doesn’t feel like it’s quiet.

 

It’s when Lena’s brushing her teeth later that night and gets a glob down her chin and Kara laughs, takes a piece of towelling and wipes it off gently, makes a quip about proper hygiene, that Lena feels logic telling her to act.

 

She doesn’t. She makes a quip right back, whip smart and charismatic even while standing in a bathroom with fuzzy slippers and having just had toothpaste drool down her chin seconds ago, and Kara still blushes.

 

No one bothers them that night. Kara falls asleep fast with one arm wrapped protectively around Lena’s waist and the other placed under her pillow. Lena listens to her breathing and leans into the steady rise and fall of her chest. She should’ve told her. She should’ve let the words out. She should’ve -

 

Her eyes close near dawn.

  


.

  


Love is a chemical, and chemicals usually have equations attached to them. Unfortunately, there’s no equation on how to tell someone that you love them. Lena’s checked.

 

Probability states that she can never have more than one night alone with Kara, undisturbed. But fortune is a fickle thing when it comes to love and does not play into Lena’s hands.

 

The next two weeks are torture because Kara’s driving her crazy in the good way. There are all these moments, these silly little moments that shine like gold and Lena just wants to snap them up and line her pockets with them before they’re gone, and more importantly, she just wants to get those words off of her chest. Those little moments are the perfect time to do that. Lena lets them all pass, helplessly, frustratingly, maddeningly.

 

There was that time they went to the movies and Kara looked breathtaking under the city lights, her hair like a halo and eyes so light against the dark.

 

There was that time Kara swooped in on Lena’s balcony after midnight in full costume, haunted and pained but beautiful.

 

There was that time where they had a spat and after they had made up Kara was pliant, sleep-heavy and so, so ethereal that Lena felt the galaxy shift around her.

 

Perhaps she did have good fortune. She just didn’t know how to use it.

 

So she does what she does best, and she makes a plan. She outlines a chart and everything, complete with post-it-notes and red marker. Her deadline is the end of the week on Friday. Lena nods at the chart when it’s done, then promptly hides it before her ten o’clock meeting with the German investors.

 

The week drags with nerves and the spontaneity of life dictates that not all things will go to plan, which they don’t.

 

She scraps her plan halfway through the day on Wednesday when Jess calls her to tell her about added on meetings or something or other. Her text to Kara is short, only says ‘working late, I’m sorry.’

 

She checks her phone later that evening to see Kara’s replied along with five different emojis. ‘No problem, I understand. I’ll save the bottle of wine’ is followed by some cute faces and a heart.

 

Lena feels the familiar tug on her heartstrings and her fingers hover over the keyboard, debating, before shutting her phone off and taking out her notes for a meeting.

 

Kara is in full costume when she gets home. Lena spots the bottle of wine on the countertop, two glasses standing next to it. She opens her mouth to offer her a drink but Kara’s already nodded off on the couch, cape draped around her body. Lena smiles fondly, wine forgotten, and tucks in the corners as best she can. She presses a kiss to her temple and hopes Kara gets at least a little bit of her message. It’s mostly just wishful thinking but Lena wishes anyways.

 

Friday arrives and nothing has progressed. Lena racks her brain. How to tell someone something so wonderful and terrifying without coming off like an idiot.

 

Dinner is a leftover chicken recipe that Kara had attempted earlier in the week (“Ina Garten makes everything look easy, it’s just not fair”). Lena insists it’s not bad, which it isn’t, and Kara holds her hand over the table. The windows are open and the city sounds drift up and mix with the radio they have playing in the background. Lena’s changed out of her office clothes and into one of Kara’s soft college sweatshirts. Everything is grossly domestic and Lena wonders when she started to be okay with that.

 

There is a moment, when your heart takes over for your head, and you have no choice but to follow through with whatever nonsense is about to spill out of your mouth.

 

Lena looks at Kara, her hair in a messy bun and a smudge of sauce on her lips, and she knows. She sits up a little straighter and clears her throat -

 

“Kara,”

 

“Yes?”

 

“I -”

 

Kara’s phone buzzes. Lena has never hated a sound more in her life.

 

The routine begins again. Kara apologizes profusely, checks her phone even though they both know who’s calling, and stands up, her gaze hardening and her eyes jumping to the window behind them.

 

The probability that Lena gets alone time with Kara -

 

Kara darts away from her seat and even though she’s moving fast Lena sees time slow down, sees Kara move, ready to transform into Supergirl, sees her ready to fly away, sees her fly away like she’s always done and what she always will do and Lena, and Lena -

 

“Wait,” she calls out and Kara stops midway out of her seat, still messy bun and smudged mouth. Her eyes are wide.

 

“What?” she says, hands in front of her. Lena falters.

 

“I,” her breath catches in her throat. Kara looks like she wants to stay but she’s mostly exasperated, shoulders hunching and nose squishing up.

 

Lena panics.

 

She gets out “I love you,” in a hurried rush at the same time Kara says “I have to go.”

 

Kara’s face goes blank. “You what?” It comes out soft.

 

Lena feels red all over. Her usual eloquence is gone and replaced with a foreign tongue, words sloppy and rolling around her slow brain. She opens her mouth once, twice, and nothing. It’s so _silly_ and she feels so young.

 

Kara stands before her, glasses off and hair now wild and out of its tie. She takes the steps it takes to get to her side and then she’s wrapping Lena into a proper hug, Lena’s ear to her heart so she can feel how fast it’s beating. A kiss is planted on her head and Lena’s eyes flutter close before she realizes -

 

“You should be going, I’m so sorry.” Lena stutters, feels terrible for wasting her time like this.

 

Kara shakes her head. “I’m fast.” Lena laughs into her shirt.

 

Kara takes Lena’s face in her hands, kisses her like it was she who was made from the stars. “I’ll be back soon,” Kara promises her. “And we can finish this later, but for now, I love you too.” She’s off in a flurry of shapes and sounds and then she’s gone in gush of wind. Lena touches her fingers to her lips and walks in a trance to the window.

 

Outside, the sun is setting, sending glorious rays of yellow and orange across the sky, and there’s Supergirl, flying higher and higher until the familiar crack of the sound barrier breaks and she’s gone once more.

 

Lena breaks out into a ridiculous, cheesy grin.

  


.

  


Later, they’re sitting on the roof, the bottle of wine opened and Kara’s head in Lena’s lap. She’s laughing hard, wonderful and free and Lena hasn’t stopped smiling since dinner.

 

“Wait, wait,” Kara wheezes and motions with her hand to go back. “You made a chart to figure out when to tell me that you loved me?” She wiggles in Lena’s lap with laughter. “You nerd, oh my gosh.”

 

“It made sense at the time,” Lena admits and finishes off her drink. “I do everything logically.”

 

Kara softens, reaches a hand out to Lena’s face. “Yeah, you do.”

 

“What I did earlier wasn’t logical.” This throws Kara back into a fit of giggles.

 

“You looked like you were going to pee yourself.”

 

“I might’ve if you’d have given me more time.” Kara sits up then and kisses her. It’s a movie kiss, the kind reserved for the end of the film before the credits roll in. Lena sighs into it, feeling weightless.

 

They break apart and Kara’s eyes reflect the stars above their heads.

 

“I’m glad it wasn’t,” she whispers. Lena kisses her forehead.

 

“Me too.”

 

The sky is clear and they lean into each other underneath it, the odds, for once, in their favor.

  


.

  
  
  



End file.
